At present, photographic paper used for printing is supplied in two different forms: either by format as individual sheets, or as rolls which are generally cut after processing. For the latter use, the rolls are of different sizes, adapted to the machines which use them.
Presentation in rolls has made it possible to increase productivity. However, the printing machines need to be installed in dark rooms, to allow the machines to be loaded, since photographic paper must be protected from light. During production, the rolls are obtained by cutting a sheet of large width, e.g. &gt;1 m, longitudinally into individual webs having a relatively narrow width, e.g. 95 mm, 102 mm, 127 mm, or more, which are wound up. The rolls are then individually packed in lightproof sleeves, e.g. as referred to in U.S. Pat. No. 4,876,125. At the time of use, the rolls have to be removed from their packing and positioned in the machines. All these operations must be carried out in the dark, and they are time consuming.
To improve the efficiency of the machines, packing has been designed, adapted to each machine. These types of packing, known as cartridges, are described, for example in U.S. Pat. No. 4,741,439. These cartridges make for easy use of the machine, since there is no longer the need for a room which can be put into total darkness when positioning the photographic paper in the machine. However, the roll lengths are limited and, at the time of their use, it is necessary to renew the cartridges frequently and to connect the webs to one another.
To increase productivity on the machines, one method is to increase the size of the rolls. However, the weight of the rolls becomes heavy and, on account of this, it becomes tedious to handle them, both when packing and removing them from the packing. At preset, rolls of up to approximately 500 m are used. The weight of these rolls is greater than 10 kg and the diameter is wider than 40 cm.
In view of their dimensions, the rolls offer greater stability when their axis is directed vertically. However the printing machines currently available on the market use rolls whose axes are directed horizontally. One purpose of the invention is therefore to avoid having to tilt the rolls.